The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 11, 1991
Filed:
Dec. 19, 1989
Edward J Pope, Lake Sherwood, CA (US);
Yoji Sano, Thousand Oaks, CA (US);
Shi-ho Wang, Newbury Park, CA (US);
Arnab Sarkar, West Hills, CA (US);
Orion Laboratories, Inc., Camarillo, CA (US);
Abstract
An improved sol-gel process is disclosed for fabricating large monoliths of silica or ceramic material, which are substantially free of cracks. Following formation of the gel, but before the gel is dried, the gel is subjected to a hydrothermal aging treatment, in which it is heated in an autoclave to a temperature of between 100.degree. and 300.degree. C., for a time duration of at least about one hour. This hydrothermal aging treatment causes silica (or ceramic) particles to migrate and fill small pores in the porous gel matrix, such that the average pore size increases and capillary forces encountered in the subsequent drying step are reduced to a point where cracking of the gel is substantially eliminated.